Rudder and propeller drive shaft support assembly



Jan. 16, 1962 c. D. VAN PATTEN 3,016,870

RUDDER AND PROPELLER DRIVE SHAFT SUPPORT ASSEMBLY Filed April 6, 1959 2 Sheets-Sheet 1 IN V EN TOR. Char/es 0. (/0/7 Pa/zen Q WQMQ L fiTTORNEY Jan. 16, 1962 c. D. VAN PATTEN 3,016,870

RUDDER AND PROPELLER DRIVE SHAFT SUPPORT ASSEMBLY 2 Sheets-Sheet 2 Filed April 6. 1959 INVENTOR. Char/es 0. Van Pa f/en [BM HTTORNE Y 3,016,870 RUBBER AND PROPELLER DRIVE SHAFT SUPPORT ASSEMBLY Charles D. Van Patten, Carp Lake, Mich. Filed Apr. 6, 1959, Ser. No. 804,228 S Claims. (Cl. 115--35) This invention relates to an improved rudder and propeller drive shaft support assembly for a boat and more particularly concerns an improved assembly consisting of a boat rudder having mounted thereon a universal trun nion hearing which is adapted to provide support for the rear or terminal portion of a propeller drive shaft.

One of the probelms of designing and constructing a high speed commercial or pleasure motorboat is that of providing adequate support for the rearward portion of the propeller drive shaft of the boat without introducing structures which cause considerable drag. Heretofore an assembly offering adequate support but producing little drag has not been available.

One type of structure widely used however is that employing struts which project downwardly from the hull in support of a fixed bearing body adapted to support the propeller drive shaft at a point somewhat ahead of the propeller. This structure produces a great deal of drag.

In each of various devices employed to eliminate the need for projecting struts the rudder has been adapted to hold a bearing body in which is journalled the rear or end portion of the propeller drive shaft at a point back of the propeller itself. But these rudder-bearing assemblies have not been entirely satisfactory.

In one such type of rudder-bearing assembly there is employed a bearing body supported from the rudder by trunnions which hold the bearing body at a fixed angle to the vertical direction. The fixed angle type bearing assembly must be especially made for each installation, as a stock design is not readily adapted to various hull designs, and further, great care must be exercised in mounting the assembly on the boat lest improper alignment of the bearing and propeller drive shaft cause rapid bearing wear.

In another type of assembly there is employed a selfaligning trunnion-mounted bearing body held by a gimbalring arrangement which permits of easier installation of the rudder and bearing assembly and provides good support for the propeller drive shaft, but the bearing body is supported from one end only and there is -a tendency for the bearing to wear unevenly at different shaft speeds so that the bearing surface no longer is cylindrical in form but becomes shaped somewhat like an hour-glass. This type of assembly has the additional disadvantages that it is costly to manufacture and it does not overcome the drag problem as it presents a large frontal surface to the water.

It is therefore an object of the invention to provide a rudder and propeller drive shaft support assembly which when properly mounted on a boat provides suitable support for the propeller drive shaft of the boat and is adapted to cause little frictional resistance when drawn through water.

It is another object of the invention to provide a rudder and propeller drive shaft support assembly having as an essential part a trunnion bearing which is self-aligning and which presents litle frontal surface toward the direction of the front of the boat.

Another object of the invention is to provide a rudder and propeller drive shaft support assembly which is adapted to allow a suficient latitude in the precision of the alignment thereof with the propeller drive shaft'of a boat whereby the assembly is readily and quickly installed.

rates Patent f Another object of the invention is to provide a rudder 3,016,870 Patented Jan. 16, 1962 and propeller drive shaft support assembly which is adapted to be installed on boats of varied hull design without tedious or costly modification.

Still another object of the invention is to provide an improved self-aligning trunnion hearing which is adapted to support the propeller drive shaft of a boat from the rudder of the boat.

A further object of the invention is to provide a selfaligning trunnion hearing so designed as to require only simple drilling and milling operations to produce from easily cast or extruded forms.

Other objects and advantages will in part be obvious or in part pointed out hereinafter.

In the accompanying drawings illustrating one of the possible embodiments of the invention,

FIGURE 1 is a fragmentary side elevation of the lower part of the rear portion of a boat having mounted thereon the rudder and propeller drive shaft support assembly of the invention, the assembly serving as supporting means for the propeller drive shaft of the boat,

FIGURE 2 is a side elevation of the apparatus of the invention shown on a larger scale than in FIGURE 1,

FIGURE 3 is a fragmentary side elevation on a still larger scale and partly in section of the trunnion bearing assembly employed in the apparatus of the invention,

FIGURE 4 is a sectional elevation taken along the line 44 of FIGURE 3,

FIGURE 5 is an isometric view of a rotatable support member from which the trunnion bearing body is pivotally supported,

FIGURE 6 is an isometric view of a rotatable guide member by means of which transverse motion of the trunnion bearing body is restricted,

FIGURE 7 is an isometric view of a trunnion bearing body,

FIGURE 8 is a top plan view of a suitable form of attaching lug which maybe used to attach a trunnion bearing assembly to a rudder.

Similar numerals refer to similar parts throughout the several views of the drawings.

In accordance with the invention, the apparatus is shown as including a rudder 10, of a design more simply described as a Helivar rudder, and a trunnion-bearing assembly, indicated generally by the numeral 12, attached to the rudder it] by upper and lower attaching lugs 14, 16. As shown in FIG. 1, the rudder It is mounted at the stern 18 of the boat by means of a conventional tiller, indicated generally by the numeral 20, and a lug 22 which are both pivotally mounted on a rod 24 which serves as the axis of rotation of the rudder 10. The rod 24 is in turn held in about a vertical position at about the middle of the stern 18 of the boat by an upper slotted bracket 26 and a pair of lower brackets 28, 3%. Referring more particularly to FIG. 2 it may be seen that the tiller 20 consists of a generally elongated bar having a central portion 32 disposed within and extending through the slotted portion of the upper bracket 26 and surrounding the rod 24, an extending lug portion 34 attached to the rudder 10 adjacent the upper end thereof as with nuts and bolts 36, and an oppositely extending lever arm portion 38, also shown in FIG. 2, which is adapted to extend inside the hull of the boat and engage a steering drive mechanism. The lug 22 is also attached to the rudder It as with nuts and bolts 40, generally at a point slightly above the midpoint of the vertical height of the rudder 10. A forwardly extending portion 42 of lug 22 is disposed between the pair of lower brackets 28, 30 and around the rod 24. The propeller drive shaft 44 of the boat is journalled in the bearing body 46 of the trunnion-bearing assembly 12 and supported thereby.

Referring more particularly to FIGS. 3 and 4, it may be seen that the trunnion-bearing assembly consists of a bearing body 46 and trunnions therefor in the form of a rotatable support member and a rotatable guide member Bearing body 46, as shown more particularly in FIG. 7, is in the form of a hollow cylinder or tube 57 having two integrally formed and oppositely projecting pairs of parallel spaced apart side extensions 52, 54 which project substantially radially from the cylinder 57. The one pair of side extensions 52 have aligned transverse holes 56 formed therethrough and are adapted to fit on'either side of rotatable support member 48 and be pivotally supported therefrom by means of a pin 58 which is mounted in support member 48 and extends rotatably through the holes 56.

Support member 48 as shown more particularly in FIG. 5 consists of a cylindrical shank portion 60 and a generally rectangular prism shaped head portion 62, said head portion having sides 64, edges 66 and an end 68. A hole 70 formed through the sides 64 of the head portion 62 in a direction transverse to the axis of the shank portion 60 is adapted to receive pin 58. The pin 58 is retained in a desired position within the head portion 62 by means of a setscrew 72 inserted in a drilled and tapped hole 74 which extends radially from the hole 70 to one of the edges 66 of the head portion 62. The surfaces of the head portion 62 between the edges 66 and the end 68 thereof are preferably rounded to facilitate pivotal motion of the bearing body 46 thereabout. Bearing body 46 is also preferably grooved between side extensions 52, as by a milling machine, so as to ensure clearance about the said rounded surfaces of the head portion 62 and also to achieve a more compact struc- 'ture.

Guidemernber 50 as shown more particularly in FIG. 6 consists of a cylindrical shank portion 76 and a head portion 78 which extends transversely across one end 80 of the shank portion 78. The other pair of side extensions 54 of the bearing body 46 are adapted to slideably engage therebetween the head portion 78 of the rotatable guide member 50 as hearing body 46 is moved pivotally about the pin 58.

In a preferred embodiment of the invention the bearing body 46 is also grooved arcuately between the side extensions 54, as by a milling machine, so as to form a slot 82 which extends in the longitudinal direction of cylinder 57 and therethrough the wall of the cylinder about midway between the ends 84 thereof. It is desired in this embodiment to allow a clearance between the head portion 78 of guide member 50 and the arcuate surfaces 85 of the grooved portion of the bearing body, whereby water is permitted ready access to the interior of the bearing to lubricate the bearing surface. To this end, that is, of employing water as a lubricant, a conventional hollow cylindrical bushing 86, such as one formed of synthetic resin-bonded fibrous material, is provided with a series of holes 88 and press-fitted to the interior surface of the tube portion 57 of the bearing body 46, the holes 88 being aligned with the said slot 82. If desired other means of lubricating the hearing, as with a hydrocarbon or graphite base .lubricant, may be employed in which case, of course, the bushing 86 is not critically provided with the said holes 88.

The support member 48 and the guide member 56, which together, as indicated above, serve as trunnions for the bearing body 46, are rotatably mounted in coaxially aligned holes 90, 92 formed in the projecting end portions 94, 96 of the attaching lugs 14, 16. The holes 90, 92 may be provided with non-metallic bushings 98, 100 if desired. Support member 48 is retained in hole 90 by a cotter key 102 inserted in the small hole 104 formed transversely adjacent the end 106 of the shank portion 60 of the support member. Washers 108, 11G mounted on shank portion 60 between the cotter key 102 and the lug 14 and between the attaching lug 14 and the head portion 62 of support member 48 may be used if desired 4 to assure easier rotation and longer service life of the apparatus.

Guide member 5% is similarly retained by a cotter key 112 inserted in the hole 114 in the shank portion 76 of the guide member. The washers 1.16 and 118 are employed in a manner similar to washers 188 and 110.

The preferred form of attaching lug 14, as shown more particularly in FIG. 8, is a forked element having a streamlined end portion 94 and extending therefrom two substantially parallel elongated spaced apart strap or bar portions 120 having holes 121 for fastening means formed therethrough and adapted to fit on either side of the rudder 10. The attaching lug 16, having an end portion 96, is provided with similar bar portions 122. The attaching lugs 14, 16 are mounted on the rudder 10 near the lower end 123 thereof in about a horizontal plane and in parallel spaced apart relation above and below, respectively, a large notch 124 cut out of the leading edge 126 of the rudder with end portions 94, 96 extending forwardly of the rudder. Both attaching lugs 14, 16 are attached to the rudder it by slot-headed bolts 128 which each extend through a hole in one bar portion 120 or 1 22, and the rudder 1t) and engage a drilled and tapped hole in the opposite, that is, complementary, bar portion, though other fasteners such as rivets may be used if desired.

For the apparatus of the invention to operate properly it is essential that in mounting attaching lugs 14 and 16 on the rudder 10 that the holes 94 92 in the end portions 4, 96 of the lugs are not only mutually aligned but also that the holes 90, 92 are aligned with the pivotal axis of the rudder 10 itself as represented by rod 24.

Further it is to be desired that the side extensions 52 of the bearing body 46 be constructed or formed closer to one of the ends 84 of the cylindrical body portion 57 rather than at the midpoint, preferably at a point between the midpoint and half the distance to one of the ends and more preferably at a point of distance from the midpoint that is between /5 and of the distance from the midpoint to the ends. In installing the apparatus of the invention having such a bearing body, the bearing body is rotated on its trunnions so that the shorter part of the cylindrical body portion extends forwardly, that is, toward the front or how of the boat, whereby on pivoting the bearing body about the pin 58 to accommodate the usual propeller shaft angle off the horizontal the longer part of the bearing body is brought down and forwardly with respect to the boat and the mass of the bearing body itself becomes approximately centered along the common axis of the trunnions, that is, rotatable support member 48 and rotatable guide member 50. This preferred form of bearing body is believed to assure a freer self-aligning action of the trunnion-bearing assembly as well as easier pivotal motion of the rudder.

While the apparatus of the invention may be constructed of various structural materials, it is obviously to be preferred that the structural materials be selected from those that are resistant to corrosion by water. For example, the rudder, tiller, and lugs are desirably formed of aluminum alloy while the bearing body, support memher and guide member are best formed of bronze [brass]. However, other structural materials may be employed, if so desired. The bearing surface is desirably formed from plastic material which may or may not be self-lubricating, or from materials lubricated by water. The particular material will be dependent upon the particular application used.

An important feature of the invention is the achievement of a narrow profile or frontal surface which the assembly presents to the water during forward movement of the assembly. This feature of the invention is more clearly understood with references to FIG. 4 of the drawings in which the profile is illustrated.

Among the advantages of the invention are the (1) improved stability of water flow around the rudder when it is moved at any speed causing less flutter and stress on the rudder, (2) the increased bearing life resulting from the easy self-aligning action of the improved trunnion bearing, and (3) the mutual support given both to the rudder and the propeller shaft.

having thus described the apparatus of the invention it is obvious that many modifications thereof may be made Without departing from the spirit of the invention the scope of which is intended to be limited only by the hereafter appended claims.

fthat is claimed is:

1. An improved rudder and propeller drive shaft support assembly comprising a rudder pivotally attached to the rearward portion of a boat and a propeller drive shaft leading from the bottom of said boat in a rearward direc tion, the rearward portion of said propeller drive shaft being positioned Within a trunnion bearing mounted in said rudder at the bottom portion thereof by means of an upper trunnion above said trunnion bearing and a lower trunnion below said trunnion bearing, said trunnion bearig being pivotally attached to said upper trunnion and said trunnion bearing slideably engaging said lower trunnion, said trunnions being rotatably mounted on said rudder in a coaxial relationship to the pivot wherein said rudder is attached to said boat.

2. An improved rudder and propeller drive shaft support assembly comprising in combination a rudder and a trunnion-bearing assembly, attaching means for attaching said trunnion-bearing assembly to said rudder adjacent the forward edge and near the lower end of said rudder, said trunnion-bearing assembly comprising a support member and a guide member, each rotatably mounted in coaxial relation in said attaching means for attaching the trunnion-hearing assembly to said rudder, and a bearing body disposed between said support member and said guide member, said bearing body being pivotally attached to said support member and adapted to slideably engage said guide member, said bearing body having an internal bearing surface adapted to receive the end portion of a propeller shaft, and said trunnion-bearing assembly and said rudder having a common axis of rotation.

3. The improved rudder and propeller drive shaft sup-' port assembly as in claim 2 in which the bearing body is longitudinally slotted and the bearing body is provided with a bushing having a plurality of holes therethrough, said holes being positioned in register with said longitudinal slot whereby the bearing body is adapted to be water lubricated.

4. The improved rudder and propeller drive shaft support assembly as in claim 2 in which the bearing body portion comprises a generally cylindrical body portion having a first and a second pair of oppositely projecting parallel spaced apart side extensions which extend substantially radially from said cylindrical body portion, said first pair of side extensions being pivotally attached to said rotatable support member whereby said bearing body is pivotal about a horizontal axis transverse to the cylindrical body portion thereof, and said second pair of side extensions being adapted to slideably engage said rotatable guide means.

5. The improved rudder and propeller drive shaft support assembly as in claim 4 in which the said bearing body is longitudinally slotted between said second pair of side extensions.

6. The improved rudder and propeller drive shaft support assembly as in claim 4 in which the said first pair of side extensions of said bearing body extend from the cylindrical body portion at a point between the midpoint of the length of the cylindrical body portion and one-half the distance to the end thereof.

7. An improved rudder and propeller drive shaft support assembly comprising, in combination, a rudder, a trunnion-bearing assembly, and upper and lower attaching means for attaching said trunnion-bearing assembly to said rudder adjacent the forward edge and near the lower end of the rudder; said trunnion-bearing assembly comprising a support member and a guide member, each rotatably mounted in coaxial relation, respectively, in said upper and lower attaching means, and a bearing body disposed between said support member and said guide 7 member; said bearing body comprising a generally hollow cylindrical body portion having an upper and a lower pair of parallel spaced apart longitudinal side extensions extending substantially radially therefrom; said upper pair of side extensions being pivotally attached to said support member whereby said bearing body is pivotal about a horizontal axis transverse to the cylindrical body portion; said lower pair of side extensions being adapted to slideably engage said guide means; said rudder being provided with a notch between said upper and lower attaching means whereby said bearing body, support member and guide member may be freely rotated without said bearing body striking said rudder; and said rudder, support member and guide member having a common axis of rotation.

8. An improved rudder and propeller drive shaft support assembly as in claim 7 in which the cylindrical body portion of said bearing body is provided with a longitudinal slot therethrough the wall of the cylindrical body portion between the lower pair of side extensions and said cylindrical body portion is provided with a bushing having a plurality of holes therethrough, said holes being in register with said longitudinal slot, whereby the bearing body is adapted to be water lubricated.

References Cited in the file of this patent UNITED STATES PATENTS 326,789 Roberts Sept. 22, 1885 1,063,388 Robbins June 3, 1913 2,316,022 Rippingille Apr. 6, 1943 

